Determining an accurate position of a mobile device such as a smart phone is important in providing location based services. The location of a smartphone may be determined using the service provider's network infrastructure in combination with measurements provided by the smartphone. Observed time difference of arrival (OTDOA) is a positioning feature introduced in the 3rd generation partnership project (3GPP) Release 9 evolved universal terrestrial radio access (E-UTRA), also referred to as long term evolution (LTE). OTDOA is a multilateration method in which a user equipment (UE), such as a smartphone, measures the time difference between specific signals from several eNodeBs (base stations) and reports these time differences to an evolved serving mobile location center (ESMLC) in the LTE network. The ESMLC calculates the UE's position based on such time differences and knowledge of the eNodeB's location.
OTDOA-based positioning has been an integral part of long term evolution (LTE) networks. The increasing usage of smartphones and location based services has made more precise positioning requirements desirable, especially indoors where global positioning system (GPS) signals may not be available. 3GPP Release 14 has sought to achieve higher positioning resolution and accuracy through a work item to enhance the OTDOA-based positioning method in existing LTE networks in which the resolution of the positioning report sent by the UE is increased. In general, the positioning accuracy requirements for LTE are expected to become more stringent in future 3GPP releases.